Engine system having coolant control valve

ABSTRACT

An engine system having a coolant control valve unit includes a valve housing in which a passage having a coolant supplied from one side of the passage and exhausted to another side of the passage is formed, a valve configured to rotate with reference to a rotation center shaft, in which a closing portion closing the passage according to a rotation position and an opening portion opening the passage are formed in the valve with a predetermined interval in a rotation direction, an actuator configured to rotate the valve with reference to the rotation center shaft, and a controller configured to control the actuator according to driving conditions, and a bypass passage penetrating the closing portion of the valve may be formed in a state that the closing portion closes the passage.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims the benefit of priority to Korean Patent Application No. 10-2016-0106269 filed on Aug. 22, 2016 with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to an engine system having a coolant control valve unit which improves a cooling efficiency and consumption efficiency of the engine by respectively controlling a coolant supplied from a cylinder head and a cylinder block of the engine.

BACKGROUND

An engine generates a rotation force by combusting fuel, and the remaining energy from the combustion of the fuel is exhausted as heat energy. In particular, a coolant absorbs heat energy while circulating through the engine, a heater, and a radiator, and discharges the absorbed heat energy to the outside.

When a coolant temperature of the engine is low, viscosity of the oil is increased so that a frictional force is increased, fuel consumption is increased, and a temperature of an exhaust gas is slowly increased so that time for activation of a catalyst is extended, and accordingly, quality of the exhaust gas may be deteriorated. Furthermore, time for normalization of operation of the heater is extended so that a passenger or a driver may feel cold.

When the coolant temperature of the engine is excessively high, knocking occurs, and ignition timing needs to be adjusted for suppression of the occurrence of knocking, thereby causing operation deterioration. In addition, when a temperature of lubricant is excessively high, lubrication performance may be deteriorated.

Thus, one integrated flow control valve that controls several cooling elements is applied to maintain a temperature of the coolant at a specific portion of the engine to be high and a temperature of the coolant at other portions to be low.

Further, coolant separation cooling method controlling coolant passing through a cylinder head and coolant passing through a cylinder block respectively is introduced, and the cylinder head is controlled by relatively low temperature and the cylinder block is controlled by relatively high temperature, therefore, fuel consumption may be reduced and cooling efficiency may be improved.

Meanwhile, a coolant temperature sensor sensing temperature of the coolant exhausted from the cylinder head is disposed. To improve temperature sensitivity of the coolant temperature sensor, a bypass hole is formed at a valve so that the coolant flows in a state that the valve is closed, however, a deviation between real temperature and sensing temperature of the coolant may be increased because of distance difference between the bypass hole and the coolant temperature sensor.

The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

SUMMARY

The present disclosure has been made in an effort to provide an engine system having a coolant control valve unit having advantages of being capable of improving precision of controlling by reducing deviation between a sensing temperature sensed from a coolant temperature sensor and real coolant temperature.

As described above, an engine system having a coolant control valve unit according to an exemplary embodiment of the present disclosure includes a valve housing in which a passage having a coolant supplied from one side of the passage and exhausted to another side of the passage is formed, a valve for rotating with reference to a rotation center shaft, wherein a closing portion closing the passage according to a rotation position of the valve and an opening portion opening the passage are formed in the valve with a predetermined interval in a rotation direction, and an actuator for rotating the valve with reference to the rotation center shaft, and a controller for controlling the actuator according to driving condition, and a bypass passage penetrating the closing portion of the valve may be formed in a state that the closing portion closes the passage.

An exterior circumference of the closing portion of the valve may be formed in a sphere shape, and the opening portion may be formed in a circular shape along a circumference of the passage.

The engine system having a coolant control valve unit according to an exemplary embodiment of the present disclosure may further include a connecting member integrally connecting an upper portion with a lower portion of the valve, and the opening portion may be formed between the closing portion and the connecting member.

The engine system having a coolant control valve unit according to an exemplary embodiment of the present disclosure may further include a pipe member integrally connecting a lower end portion of the connecting member with an inner side surface of the closing portion, and the bypass passage may be formed at a center portion of the pipe member.

The engine system having a coolant control valve unit according to an exemplary embodiment of the present disclosure may further include a coolant temperature sensor disposed at the valve housing to sense a temperature of a coolant passing through an inlet of the pipe member connected with the lower end portion of the connecting member.

A head coolant inlet that a coolant is supplied from a cylinder head of the engine and a block coolant inlet that the coolant is supplied from a cylinder block of the engine may be formed at the valve housing, and the valve may control the coolant supplied from the head coolant inlet.

The engine system having a coolant control valve unit according to an exemplary embodiment of the present disclosure may further include a block thermostat operating according to a coolant temperature to open or close the second passage.

The coolant supplied from the head coolant inlet and the block coolant inlet may be respectively distributed to a heater core conducting heat exchange with indoor air, an oil cooler conducting heat exchange with oil circulating the engine, and a radiator conducting heat exchange with outdoor air.

The engine system having a coolant control valve unit according to an exemplary embodiment of the present disclosure may further include a radiator thermostat controlling the coolant operated by the controller and supplied to the radiator according to temperature of the coolant exhausted from the radiator.

The coolant exhausted from the heater core, the oil cooler, and the radiator may be pumped to the cylinder block of the engine, and the pumped coolant may circulate through the cylinder head and the cylinder block.

An engine system having a coolant control valve unit according to an exemplary embodiment of the present disclosure may include a valve housing including, at one side thereof, a head coolant inlet that a head coolant is supplied from a cylinder head of the engine and a block coolant passage that a block coolant is supplied from a cylinder block of the engine, wherein a first passage connected with the head coolant inlet and a second passage connected with the block coolant passage are formed in the valve housing; a mixing housing disposed at another side of the valve housing, in which the coolant passing through the first and second passages gather, and configured to distribute the coolant to respective coolant demanding elements; a valve for rotating with reference to a rotation center shaft, wherein a closing portion closing the first passage according to a rotation position of the valve and an opening portion opening the passage are formed in the valve with a predetermined interval in a rotation direction; a block thermostat operating according to a coolant temperature to open or close the second passage; an actuator for rotating the valve with reference to the rotation center shaft; and a controller for controlling the actuator according to driving conditions, a bypass passage may be formed to penetrate the closing portion of the valve in a state that the closing portion closes the passage.

According to the exemplary embodiments of the present disclosure, the closing portion and the opening portion are formed in a predetermined interval in a rotation direction at the valve, one end portion of the pipe member is integrally connected with the closing portion, the bypass passage is formed along the center portion of the pipe member, and the coolant temperature sensor is disposed at the inlet of the other end of the pipe member. Therefore, accuracy of sensing the coolant temperature may be improved.

Further, the pipe member is integrally formed at the closing portion of the valve, and the coolant penetrates easily through the bypass passage in a state that the closing portion of the valve closes the coolant passage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a coolant flow in an engine system having a coolant control valve unit according to an exemplary embodiment of the present disclosure.

FIG. 2 is a schematic perspective view of a coolant control valve unit according to an exemplary embodiment of the present disclosure.

FIG. 3 is a perspective view of a valve disposed at a coolant control valve unit according to an exemplary embodiment of the present disclosure.

FIG. 4 is a front view of a valve disposed at a coolant control valve unit according to an exemplary embodiment of the present disclosure.

FIG. 5 is a graph showing effect of an engine system having a coolant control valve unit according to an exemplary embodiment of the present disclosure.

<Description of symbols> 100: coolant control valve unit 102: valve housing 105: cylinder head 115: oil cooler 120: heater core 125: radiator thermostat 130: radiator 140: coolant pump 110: cylinder block 200: coolant temperature sensor 210: block thermostat 215: block coolant inlet 220: head coolant inlet 230: actuator 250: valve 252: mixing housing 300: closing portion 302: rotation center shaft 310: opening portion 312: connecting member 320: pipe member 325: bypass passage

DETAILED DESCRIPTION

An exemplary embodiment of the present disclosure will hereinafter be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram illustrating a coolant flow in an engine system having a coolant control valve unit according to an exemplary embodiment of the present disclosure.

Referring to FIG. 1, the engine system includes a cylinder head 105, a cylinder block 110, a coolant control valve unit 100, a heater core 120, an oil cooler 115, a radiator 130, a radiator thermostat 125, and a coolant pump 140.

Further, the engine system includes a controller (not shown) controlling the coolant control valve unit 100, the radiator thermostat 125, and the coolant pump 140, and the controller may respectively control the coolant control valve unit 100, the radiator thermostat 125, and the coolant pump 140. Further, unexplained portions refer to known techniques.

Coolant pumped by the coolant pump 140 is pumped to one side of the cylinder block 110, a portion of the pumped coolant passes the cylinder block 110, and the remains are distributed to the cylinder head 105.

The coolant passing the cylinder head 105 and the cylinder block 110 is respectively supplied to both sides of the coolant control valve unit 100, and the coolant control valve unit 100 distributes the supplied coolant to the heater core 120, the oil cooler 115, and the radiator 130. Here, the coolant control valve unit 100 may respectively control the head coolant passing the cylinder head 105 and the block coolant passing the cylinder block 110.

The radiator thermostat 125 may operate by the controller or the coolant temperature to control the coolant passed the radiator, and the coolant passed the heater core 120, the oil cooler 115 and the radiator 130 recirculates to intake side of the coolant pump 140 again. The structures and functions of the heater core 120, the oil cooler 115 and the radiator 130 refer to known technologies.

FIG. 2 is a schematic perspective view of a coolant control valve unit according to an exemplary embodiment of the present disclosure.

Referring to FIG. 2, the coolant control valve unit 100 includes a valve housing 102, an actuator 230, a valve 250, a head coolant inlet 220, a block coolant inlet 215, a coolant temperature sensor 200, and a block thermostat 210.

On the front surface of the valve housing 102, the head coolant inlet 220 that the coolant is supplied from the cylinder head 105 and the block coolant inlet 215 that the coolant is supplied from the cylinder block 110 are respectively formed, and a mixing housing 252 that the coolant gathers is disposed at the opposing side of the block coolant inlet 215.

The coolant gathered in the mixing housing 252 is distributed to the heater core 120, the oil cooler 115, and the radiator 130, as described above.

The head coolant supplied through the head coolant inlet 220 is gathered in the mixing housing 252 through a first passage formed in the valve housing 102, and the block coolant supplied through the block coolant inlet 215 is gathered in the mixing housing 252 through a second passage formed in the valve housing 102.

The valve 250 is disposed at the first passage, and the valve 250 rotates by the actuator 230 to open and close the first passage. Further, the block thermostat 210 is disposed at the second passage, and the block thermostat 210 operates by the coolant temperature to open and close the second passage.

The coolant temperature sensor 200 is disposed at the coolant inlet of the valve 250. The coolant temperature sensor 200 penetrates side surface of the valve housing 102 to protrude toward inside of the head coolant inlet 220.

The coolant temperature according to an exemplary embodiment of the present disclosure is disposed at the inlet of the bypass passage 325 of the valve 250 to improve performance of sensing the coolant temperature. Hereinafter, the structure of the valve 250 will be described in detail referring to FIG. 3 and FIG. 4.

FIG. 3 is a perspective view of a valve disposed at a coolant control valve unit according to an exemplary embodiment of the present disclosure, and FIG. 4 is a front view of a valve disposed at a coolant control valve unit according to an exemplary embodiment of the present disclosure.

Referring to FIG. 3 and FIG. 4, the valve 250 includes a virtual rotation center shaft 302, a closing portion 300, an opening portion 310, a connecting member 312, and a pipe member 320.

The valve 250 rotates with reference to the rotation center shaft 302, and the closing portion 300 is formed at a rear side with reference to the rotation center shaft 302. Further, the opening portion 310 is formed in a predetermined interval with the closing portion 300 in the rotation direction. Here, the closing portion 300 and the opening portion 310 are formed by rotation difference of about 90 degrees.

The connecting member 312 integrally connects the upper portion and the lower portion of the valve 250, the opening portion 310 is formed between the connecting member 312 and the closing portion 300, and the opening portion 310 is formed as a circular shape corresponding to the shape of the first passage.

The pipe member 320 is disposed at the lower portion of the valve 250 by a distance with the rotation center shaft 302 in a vertical direction, and the bypass passage 325 is formed at the center portion of the pipe member 320.

More particularly, the front end portion of the pipe member 320 is integrally connected with the lower end portion of the connecting member 312, the rear end portion of the pipe member 320 is integrally connected with the closing portion 300, and the bypass passage 325 is formed at the center portion of the pipe member 320.

In a state that the closing portion 300 closes the first passage, the coolant exhausted from the cylinder head 105 circulates through the head coolant inlet 220, the inlet of the pipe member 320, and bypass passage 325 to the mixing housing 252. Further, the coolant temperature sensor 200 is disposed at the inlet of the pipe member 320 to improve performance of sensing coolant temperature.

FIG. 5 is a graph showing effect of an engine system having a coolant control valve unit according to an exemplary embodiment of the present disclosure.

Referring to FIG. 5, the horizontal axis indicates a time, and the vertical axis indicates a coolant temperature.

The coolant temperature sensor output value in the open state and the direct measuring value of the coolant in the head are nearly similar. The coolant temperature sensor output value is slightly smaller than the direct measuring value of the coolant in the head.

Further, the coolant sensor output value in the close state and the direct measuring value of the coolant in the head maintain high value in the open state, and the coolant temperature sensor output value in the close state increases to follow the direct measuring value of the coolant in the head.

In other words, difference between the coolant sensor output value in the close state and the direct measuring value of the coolant in the head decreases than the difference of prior art.

While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. 

What is claimed is:
 1. An engine system having a coolant control valve unit, comprising: a valve housing in which a passage having a coolant supplied from one side and exhausted to another side of the passage is formed; a valve for rotating with reference to a rotation center shaft, wherein a closing portion closing the passage according to a rotation position of the valve and an opening portion opening the passage are formed in the valve with a predetermined interval in a rotation direction; an actuator for rotating the valve with reference to the rotation center shaft; and a controller for controlling the actuator according to driving conditions, wherein a bypass passage penetrating the closing portion of the valve is formed in a state that the closing portion closes the passage.
 2. The engine system of claim 1, wherein: an exterior circumference of the closing portion of the valve is formed in a sphere shape, and the opening portion is formed in a circular shape along a circumference of the passage.
 3. The engine system of claim 2, further comprising: a connecting member integrally connecting an upper portion with a lower portion of the valve, wherein the opening portion is formed between the closing portion and the connecting member.
 4. The engine system of claim 3, further comprising: a pipe member integrally connecting a lower end portion of the connecting member with an inner side surface of the closing portion, wherein the bypass passage is formed at a center portion of the pipe member.
 5. The engine system of claim 4, further comprising: a coolant temperature sensor disposed at the valve housing to sense a temperature of a coolant passing through an inlet of the pipe member connected with the lower end portion of the connecting member.
 6. The engine system of claim 1, wherein: a head coolant inlet that a coolant is supplied from a cylinder head of the engine and a block coolant inlet that the coolant is supplied from a cylinder block of the engine are formed at the valve housing, and the valve controls the coolant supplied from the head coolant inlet.
 7. The engine system of claim 6, further comprising: a block thermostat operating according to a coolant temperature to open or close the second passage.
 8. The engine system of claim 6, wherein: the coolant supplied from the head coolant inlet and the block coolant inlet is respectively distributed to a heater core conducting heat exchange with indoor air; an oil cooler conducting heat exchange with oil circulating the engine; and a radiator conducting heat exchange with outdoor air.
 9. The engine system of claim 8, further comprising: a radiator thermostat controlling the coolant operated by the controller and supplied to the radiator according to temperature of the coolant exhausted from the radiator.
 10. The engine system of claim 8, wherein: the coolant exhausted from the heater core, the oil cooler, and the radiator is pumped to the cylinder block of the engine, and the pumped coolant circulates through the cylinder head and the cylinder block.
 11. An engine system having a coolant control valve unit, comprising: a valve housing including, at one side thereof, a head coolant inlet that a head coolant is supplied from a cylinder head of the engine and a block coolant passage that a block coolant is supplied from a cylinder block of the engine, wherein a first passage connected with the head coolant inlet and a second passage connected with the block coolant passage are formed in the valve housing; a mixing housing disposed at another side of the valve housing, in which the coolant passing through the first and second passages gather, and configured to distribute the coolant to respective coolant demanding elements; a valve for rotating with reference to a rotation center shaft, wherein a closing portion closing the first passage according to a rotation position of the valve and an opening portion opening the passage are formed in the valve with a predetermined interval in a rotation direction; a block thermostat operating according to a coolant temperature to open or close the second passage; an actuator for rotating the valve with reference to the rotation center shaft; and a controller for controlling the actuator according to driving conditions, wherein a bypass passage penetrates the closing portion of the valve in a state that the closing portion closes the passage.
 12. The engine system of claim 11, wherein: an exterior circumference of the closing portion of the valve is formed in a sphere shape, and the opening portion is formed in a circular shape along a circumference of the passage.
 13. The engine system of claim 12, further comprising: a connecting member integrally connecting an upper portion with a lower portion of the valve; wherein the opening portion is formed between the closing portion and the connecting member.
 14. The engine system of claim 13, further comprising: a pipe member integrally connecting a lower end portion of the connecting member with an inner side surface of the closing portion; wherein the bypass passage is formed at a center portion of the pipe member.
 15. The engine system of claim 14, further comprising: a coolant temperature sensor disposed at the valve housing to sense a temperature of a coolant passing through an inlet of the pipe member connected with the lower end portion of the connecting member.
 16. The engine system of claim 11, wherein: the respective coolant demanding elements include: a heater core conducting heat exchange with indoor air; an oil cooler conducting heat exchange with oil circulating the engine; and a radiator conducting heat exchange with outdoor air.
 17. The engine system of claim 16, further comprising: a radiator thermostat controlling the coolant operated by the controller and supplied to the radiator according to temperature of the coolant exhausted from the radiator. 